Turn off the electricity to the light fixture at the home's circuit breaker panel.
Remove the thumbscrews on the fixture's base and pull the fixture away from the ceiling or wall. If the thumbscrews are too tight to turn with your fingers, use a pair of pliers.
Pull the fixture away from the wall or ceiling and loosen the wire nuts connecting the home wiring to the wiring of the fixture. If there are no wire nuts, cut the wires, leaving as much wire as possible extending from the ceiling or wall.
Loosen and remove the screws holding the fixture's mounting plate onto the wiring box in the ceiling or wall. Take the mounting plate off of the wiring box.
Wrap the bare ends of the wiring around the screws on the electrical receptacle. Wrap the black wire around the brass-colored screw, the white wire around the silver-colored screw and the bare wire around the green-colored screw. Tighten the screws.
Place the receptacle in the wiring box, lining up the mounting tabs of the receptacle with the screw holes in the box. Tighten the receptacle's screws to fasten it in place. Place an outlet cover onto the receptacle.